Morris Minor Owners Club

Hello -
I have just rediscovered a long-forgotten unopened litre bottle of Automec silicon brake fluid, still sealed and wrapped. It has been stored indoors but must be over 20 years old. Would it still be useable? and beside that, how do people feel about silicon fluid generally? I am doing a complete rebuild of brake hydraulics so now is the moment of decision whether to use silicon or not...

Silicon or DOT4 discussed many times - try the search box. Individual preference rules, but I have used silicon for many years and would not use anything else. Does not strip paint. Does not absorb water, does not need regular changing. Since swapping, I have never had a seized cylinder. Fantastic stuff. Automec should be able to advise on shelf liufe, but as it has been in my brakes for 20 years, I don't see why a sealed bottle should not last, but do check.

I would suspect a sealed bottle, in spite of it's age, should be o.k. to use. After all, the same stuff in a braking system is alleged not to require changing until 100k miles.
I have had Automec Silicone fluid in my car's braking system for about 26 years. However, I did a "flush" about 10 years ago. That was only really to make sure there was no air trapped anywhere, even thought the brakes were working fine with a "hard" pedal.
When I filled the system with it, all of the system was renewed, master cylinder, all wheel cylinders, flexile hoses and pipes. I seem to remember it not being adviseable to just change to silicone fluid from DOT 3/4 because it could affect rubber seals.
Auotomec do seem to have a website but I couldn't access it. www.automec.co.uk "server not found". Firefox, Chrome and Microsoft Edge, same result.

Mervin wrote: ↑Fri May 22, 2026 1:31 pm
Auotomec do seem to have a website but I couldn't access it. www.automec.co.uk "server not found". Firefox, Chrome and Microsoft Edge, same result.

Perhaps it was a temporary glitch, I just clicked on the hyperlink in your post and it connected.

100% correct, must have been something temporary, it's working for me now.
I was hoping there might have been some reference to shelf life there. Only a service mileage is advised.
There is a contact e-mail and phone number. Possibly they could advise on shelf life. Then maybe not for safety/liability reasons?
I have edited my previous post to add the 100k miles service interval, they advise, to cover my backside!

Many thanks for the replies. The link does indeed work and I posted a message to Automec asking about shelf life. I have not yet received a reply, however it is a good point that the product is designed to last a very long time so reasonable to assume it will have remained in good condition in the bottle.
I have looked at some of the other posts that discuss silicon; there always seem to be one or two nay-sayers so it seemed worth asking the question again.